1. Field of the Invention
This invention relates to a muffler system in general, and, more particularly, to an integrated muffler system for decreasing the noise level of a compressor and for manipulating the frequency of the soundwaves associated with the operation of a compressor to produce a more tranquil operating environment.
2. Description of the Related Art
Compressors are utilized for compressing air or other gas at a low pressure, such as atmospheric pressure, to a higher pressure for subsequent use. One such application is the use of a compressor with an oxygen concentrator, where air is drawn into the compressor from the surrounding environment through an inlet port of the compressor and then compressed and passed through an outlet of the compressor to the molecular sieves of the oxygen concentrator.
A compressor includes a housing that houses a connecting rod assembly and a piston assembly which compress the air. The piston assembly generally consists of a compressor head connected to a valve plate, a piston sleeve connected to the valve plate, and a piston within the piston sleeve that moves within the piston sleeve in an up and down cycle. Compressing the gas generates noise from a variety of sources. For instance, running the connecting rod assembly and sucking gas into the compressor during the downstroke of the piston generates noise through the compressor intake port. Many pistons utilize a reed valve in the valve plate for directing the gas flow in and out of the compressor. Air flowing through such a reed valve generates a sound that is continually repeated as a result of the reciprocating motion of the piston. Furthermore, compressing gas during the upstroke of the piston generates a noise that travels back through the compressor intake port, while the turbulent flow of the gas as it travels at high velocity into an output cylinder also generates acoustic noise in a pulse setting fashion. Accordingly, in a conventional compressor assembly, a muffler is generally connected somewhere in the compressor system for muffling the noise of the compressor.
Several attempts have been made to develop a muffler for compressors. Previously, some efforts have included placing foam filters within enclosed chambers with the gas being forced through the filters. While such mufflers generally filter very high frequencies, they have little affect on lower frequency sounds. Furthermore, these assemblies require numerous parts and typically occupy a large amount of space, which adversely impact the desirability of the muffler. Such an assembly is shown in FIG. 1 and described in greater detail below. Another possible disadvantage with such a design is that a trade-off exists between adequately muffling the noise and producing a pressure drop across the muffler. Such a pressure drop decreases the efficiency of the compressor.
Other attempts to reduce compressor noise have utilized non-dissipative mufflers for reducing sound within a specific frequency range. Such mufflers utilize a resonator that is tuned to maximize the amount of attenuation by adjusting the length and diameter of the outlet with respect to the sides of the cylinder chamber. While these types of resonators are effective, they generally require extensive design work on the particular compressor size and then only work on soundwaves of a particular frequency.
While many of these mufflers are believed to reduce the compressor noise, they are generally either difficult to design, only effectively reduce the sound associated with a particular wave frequency, or require many components which result in an increase cost of the muffler in both materials and assembly labor.
Therefore there is a need for an improved compressor muffler for a pneumatic compressor and, especially, for a compressor that is utilized in the home environment for establishing a sound spectrum that is not intrusive to the hearing of individuals.
Accordingly, it is an object of the present invention to provide a muffler assembly which is easy to manufacture.
Additionally, it is an object of the present invention to provide a muffler assembly which decreases the overall decibel level of the compressor and also improves the sound quality of the noise associated with the compressor.
Furthermore, it is an object of the present invention to provide a muffler assembly that includes a suspended attenuator for reducing the overall decibel level of the compressor by manipulating the amplitude and frequency of the soundwaves associated with a pneumatic compressor.
Furthermore, it is an object of the present invention to provide an effective muffler which does not significantly effect the overall size of a compressor or the cost of manufacturing the compressor.
It is also an object of the present invention to provide an effective muffler that does not create a significant pressure drop, thereby reducing the efficiency of the compressor.
Also, it is an object of the present invention to provide a compressor muffler system having a filter directly mounted on the compressor housing for filtering gas prior to compression.
The above objectives are accomplished according to the present invention by providing an integrated muffler assembly for a compressor that reduces the noise created by the compressor""s operation. The muffler assembly is mounted directly onto the compressor housing such that the muffler assembly and compressor housing move as a solid body. The muffler assembly includes an intake having a hollow interior that receives a first flow of gas from the ambient environment. A baffle in the hollow interior of the intake restricts the flow of gas through the intake and defines at least a portion of a plurality of fluid portals. These portals separate the first flow of gas into a plurality of flows as the gas passes from a first side of the baffle to a second side of the baffle, thereby disturbing the first flow of gas and attenuating noise.
In another embodiment of the present invention, a plurality of baffles are provided in the hollow interior of the intake for providing a tortuous path for the flow of gas through the intake, thereby blocking a line of sight for the flow of gas to an intake port of a compressor for attenuating noise.
These and other objects, features and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.